add newly added constraints to expire clear_expired_metering_data

- cascade deletes to metadata tables on meter deletion
- delete associations on object deletion
- add check to not delete user/project entries associated with Alarm

Change-Id: I24cbaea9ede6d142dc22eaf070b3f7d1f14b484a
Closes-Bug: #1258071
doc: fix formatting of alarm action types

Trivial fix to make this list be formatted correctly, highlight the
terms being described and s/http call back/HTTP callback/.

Change-Id: I00710fc7f7f389d13c3ce4c6a715de663e2c05b4
doc: remove note about Nova plugin framework

The architecture doc alludes to a Nova plugin framework which is now
considered obsolete.

See oslo-incubator review I5552b5625e26f4821464807743545ec6f5117f2b
(commit 4b78868) for more background.

Change-Id: Id170510bc3147af94941c993ffe6997c418d4be4
test code should be excluded from test coverage summary

Since the recent movement of the test code directory, now entire test
code is included in the test coverage summary, it makes a rather
strange loop, test code in the summary also shows being tested or
not tested. This patch will fix the problem so that the test
coverage summary will not show the coverage percentage for test code.

Change-Id: Ibbb4a009f01515befdd7045d6eec1afaf24ca99f
config: specify a template for mktemp

It's actually not portable to use mktemp without an argument, so let's
add a default template.

Change-Id: I5c254b12c05457d9e3ed5788dabb4c317d97b4aa
Event Storage Layer

This change adds the storage layer interfaces
necessary to implement the Event API. It also
updates the get_events call to allow multiple
trait filters.

implements bp specify-event-api

Change-Id: I7aef4a8fc9b88528479f6c0a9feab2c18945bae3
service: fix service alive checking

This change the way we check for service being alive in a more portable
way by using os.kill() with a null signal.

Change-Id: I588ab19de15b351c1de3ab28b8655e400b2a2064
Merge "test code should be excluded from test coverage summary"
Merge "doc: fix formatting of alarm action types"
Merge "doc: remove note about Nova plugin framework"
Merge "config: specify a template for mktemp"
Merge "add newly added constraints to expire clear_expired_metering_data"
Merge "Event Storage Layer"
Merge "service: fix service alive checking"